Question

Write 27.9 as a decimal

Answer 1

You have already wrote it in a decimal unless you were talking about a fraction because the fraction is 279/1000.

Answer 2

That's not the question in the picture.

The question in the picture is " 27.9 percent ", to be written
as a decimal.

Whenever you see a percent sign, it means " /100 ".

27.9% means 27.9/100 .

When you want to divide something by 100, you can just move
the decimal point two places to the left.

So 27.9 / 100 is just 0.279 .